CircuPack

Define tangencies. Get precise circle packings.

A robust Java library that computes Euclidean circle packings from triangulations. Inspired by Gerald Orick’s GOPack.

Core Idea

Supply a Triangulation that defines which circles are tangent to which. CircuPack handles all the geometry: it calculates exact radii and center positions so every specified tangency is visually perfect.

Key Features

• Simple Input: Implement the Triangulation interface to define your graph of tangencies.
• Automatic Geometry: No need to guess positions or sizes. The engine computes everything.
• Multiple Layouts: Pack into a disc (MAX_PACK), a custom polygon, or a rectangle [WIP🚧].
• Production-Ready: Stable, reliable and fast (10k circles in ~1s).

Quick Start

// 1. Define your triangulation (e.g., from Tinfour)
IIncrementalTin tin = new IncrementalTin();
// ... add vertices ...
Triangulation tri = new TinfourTriangulation(tin);

// 2. Initialize the packer
CircuPacker packer = new CircuPacker(tri);
packer.initialize();

// 3. Compute the packing
double maxError = 0.01; // max visual error (overlap, as a fraction of circle radius)
packer.riffle(maxError); // Iterate until max error is below threshold

// 4. Retrieve results
double[] radii = packer.getRadii();
double[] centersX = packer.getCentersX();
double[] centersY = packer.getCentersY();